This is far from the only arena allocator written in Rust. From the same author, a zero-unsafe arena allocator: https://github.com/fitzgen/generational-arena h

This is far from the only arena allocator written in Rust. From the same author, a zero-unsafe arena allocator: https://github.com/fitzgen/generational-arena https://github.com/fitzgen/generational-arena There are many, many arena implementations available with varying characteristics. It's disingenuous to act like Rust requires the author of an arena library to write "unsafe" everywhere.